Electrocoagulation—photocatalytic process for the treatment oflithographic wastewater. Optimization using response surfacemethodology (RSM) and kinetic study

Abstract

tIn this work, optimization of total organic carbon (TOC) removal for the treatment of lithographic waste-water by electrocoagulation followed by photocatalytic process was developed. It was used a responsesurface methodology (RSM) for the optimization of the process variables, such as current density forelectrocoagulation process, TiO2concentration for photocatalytic process, and pH in both cases. Optimalconditions for the process were obtained with TOC removal above 65% using electrochemical process by30 min of operation. A total of 25% of residual TOC was removed employing the photocatalytic process,for a total of 74% of removal of TOC from the initial value. A kinetic modeling was performed for bothprocesses to pseudo-second-order equations. The treated water is colorless and could be suitable forcleaning water in the lithographic process.